The present disclosure relates to semiconductor processing methods, and particularly to a method of ashing a patterned organic material and structures for implementing the same.
A tapered profile in a patterned hard mask layer can induce pattern-factor-dependent etch bias variations in the width of the patterns that are transferred into an underlying material layer. Typical ashing processes employing oxygen are prone to formation of such a tapered profile in a patterned hard mask layer. Further, formation of a taper in a vertical material portion can impede recessing of the vertical material portion due to residual material trapped in divots. Thus, an ashing chemistry that does not provide a tapered profile in a patterned hard mask layer is desired.